This disclosure relates to an image forming apparatus and more specifically to a technology of shifting to a standby mode.
Some image forming apparatuses have a standby mode in which start of image formation is awaited. For example, upon shifting to the standby mode, four transfer rollers are separated from photosensitive drums (switching from a four-color-pressed state to a four-color-separated state is made) to thereby suppress deterioration of the photosensitive drums, etc. and a rotation speed of a polygon motor is reduced or stopped to thereby realize energy saving. Moreover, upon the reduction or stopping of the rotation speed of the polygon motor, operation sound of the apparatus is reduced.
Shifting to the standby mode occurs upon passage of predefined standby time (for example, one minute) while the image forming apparatus is kept unoperated. For example, upon passage of one minute while the image forming apparatus is kept unoperated after ending of copying, shifting to the standby mode occurs, reducing the operation sound of the apparatus.
Moreover, some image forming apparatuses have a function of a silent mode which can be set in a desired manner by a user. Then in a case where the silent mode is set, upon the ending of copying, standby time is omitted (that is, without waiting for passage of one minute) and shifting to the standby mode occurs. As a result, the operation sound of the polygon motor can be reduced immediately after the ending of the copying.
Moreover, the switching to the four-color separated state is also performed immediately after the ending of the copying, and thus a driving sound is also generated upon the switching to the four-color-separated state immediately after the ending of the copying, thus making it possible to realize a more silent image forming apparatus thereafter.